JP7285668B2 - Robot and its brake control program - Google Patents

Description

The present invention relates to a robot and its brake control program.

Patent Literature 1 listed below discloses a control device for a robot. In this robot control device, when the servo control system is put into a non-operating state and the brakes are released to move the robot arm, the brake control unit alternately controls release and lock of the brakes to generate intermittent braking. Let
The robot control device configured in this way can suppress excessive movement of the robot arm, and furthermore, finely adjust the movement position of the robot arm and smoothly move the robot arm.

JP-A-11-179691

For example, in a horizontal multi-joint robot, height adjustment work such as origin setting work of a robot arm is performed on a vertical control axis. In this height adjustment work, intermittent braking occurs when the brake is released and the robot arm is moved upward, making it difficult to move the robot arm smoothly. Therefore, there is room for improvement.

In view of the above facts, the present invention is intended to cause a computer to execute a robot and its brake control method that can smoothly move a robot arm when the brake is released to move the robot arm in a specific direction. program.

In order to solve the above problems, a robot according to a first aspect of the present invention includes a position detection unit that detects the position of a robot arm, a brake unit that brakes the robot arm, and based on the position detected by the position detection unit. and a brake control unit that alternately activates and releases the brake unit, the brake control unit compares the position with a reference value, and receives a command to release the brake unit , when the position is equal to or less than the reference value, the actuation and release of the actuation of the brake portion are alternately performed, and when the position exceeds the reference value, the actuation of the brake portion is released.

A robot according to a second aspect of the present invention is the robot according to the first aspect, further comprising a storage unit for storing positions as position information, and the reference value is the position information stored in the storage unit before the command. It is

In the robot according to the third embodiment of the present invention, in the robot according to any one of the first embodiment and the second embodiment, the robot arm is a robot arm of a horizontal articulated robot that moves in the vertical direction. .

In the robot according to the fourth embodiment of the present invention, in the robot according to any one of the first embodiment and the second embodiment, the robot arm rotates vertically about the joint of the vertical articulated robot. It is a moving robot arm.

A program according to a fifth embodiment of the present invention is a program for causing a computer to execute a brake control method for a robot comprising a position detection section, a brake section, and a brake control section, wherein the position detection section is a robot A step of detecting the position of the arm, a step of braking the robot arm by the brake section, and a command by the brake control section to compare the position detected by the position detection section with a reference value and release the operation of the brake section. a step of alternately actuating and deactivating the braking portion when the position is below the reference value and deactivating the braking portion when the position exceeds the reference value.

According to the present invention, there is provided a program for causing a computer to execute a robot and its brake control method, which can smoothly move a robot arm when the brake is released to move the robot arm in a specific direction. can do.

1 is a perspective view illustrating a schematic configuration of a robot (horizontal articulated robot) according to a first embodiment of the present invention; FIG. FIG. 2 is a schematic configuration diagram of main parts for explaining the configuration of a robot arm and joints of the robot shown in FIG. 1; 2 is a block diagram illustrating the configuration of a brake control unit of the robot shown in FIG. 1; FIG. 4 is a flowchart for explaining a brake control method in a brake control unit shown in FIG. 3 and a program for causing a computer to execute this brake control method; FIG. 10 is a perspective view illustrating a schematic configuration of a robot (vertically articulated robot) according to a second embodiment of the present invention; FIG. 6 is a schematic configuration diagram of a principal part for explaining the configuration of a robot arm and joints of the robot shown in FIG. 5;

[First Embodiment]
A program for causing a computer to execute a robot and its brake control method according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. FIG.
Here, in the drawings, the arrow X shown as appropriate indicates the X-axis direction of the three-dimensional coordinates, the arrow Y indicates the Y-axis direction, and the arrow Z indicates the Z-axis direction. The Y-axis direction is orthogonal to the X-axis direction in the horizontal plane, and the Z-axis direction is orthogonal to the X-axis direction and the Y-axis direction. These directions are directions used for convenience in describing the embodiments, and do not limit the directions in the present invention.

(Overall Configuration of Robot 1)
As shown in FIG. 1, the robot 1 according to this embodiment is configured as a horizontal articulated robot. Specifically, the robot 1 includes a robot main body 11 including a plurality of robot arms 21 to 24 and a plurality of joints 31 to 34, and a brake control section 4. As shown in FIG.
Each component will be described in detail below.

(1) Structure of Robot Arms 21 to 24 and Joints 31 to 34 As shown in FIG. 1, in the robot body 11, the robot arm 21 is erected upward from a base portion (not shown) in the Z-axis direction. , and here it is formed in a cylindrical shape. A joint portion 31 is provided as a rotary joint at the upper end portion of the robot arm 21 . Here, only the functions of the joints 31, 32 and 34 will be briefly described, and detailed descriptions of their configurations will be omitted.

One end of a robot arm 22 extending in the Y-axis direction in the state shown in FIG. The robot arm 22 is configured to rotate and move in the horizontal direction indicated by the arrow A by a joint portion 31 . The other end of the robot arm 22 is provided with a joint portion 32 as a rotary joint similar to the joint portion 31 .

Similar to the robot arm 22 , one end of a cylindrical robot arm 23 extending in the Y-axis direction is connected to the joint 32 . The robot arm 23 is configured to rotate and move in the horizontal direction indicated by the arrow B by a joint portion 32 . A joint portion 33 is provided at the other end portion of the robot arm 23 .

The joint part 33 is configured as a translational joint as shown in FIGS. 1 and 2 . The joint portion 33 is configured to move the cylindrical robot arm 24 extending in the Z-axis direction in the vertical direction (vertical direction) indicated by the arrow C. As shown in FIG.
Specifically, as shown in FIG. 2, the joint section 33 includes a rack 331 extending vertically along the side surface of the robot arm 24 and a pinion 332 meshing with the rack 331 . A rotary shaft 333 of an electric motor 334 as a rotary drive source is connected to the rotation center of the pinion 332 .
That is, by rotating the electric motor 334 in the joint section 33, the robot arm 24 can be vertically raised or lowered via the rack and pinion mechanism.

A joint portion 34 as a rotary joint similar to the joint portion 31 is arranged at the lower end portion of the robot arm 24 . The joint part 34 is configured to rotate in the horizontal direction indicated by the arrow D. As shown in FIG. A tool such as a handpiece (not shown) can be attached to the joint 34 .

(2) Configuration of Brake Control Unit 4 Here, a program for causing a computer to execute a brake control system and a brake control method for the robot arm 24 whose vertical movement is controlled by the joint unit 33 will be described. Regarding the robot arm 22 and the like whose movement is controlled by the joint portion 31 and the like other than the joint portion 33, the brake control system and the program are basically the same, so the description will be omitted.

As shown in FIG. 3, the brake controller 4 of the robot 1 includes a host computer (Host CPU) 41, a motor control driver (MCD) 42, and a servo driver 43, respectively. In this embodiment, the brake control section 4 is constructed using a control section (controller) that controls the movement of the robot arm 24 by controlling the motion of the joint section 33 .
On the other hand, in the robot main body 11 , the electric motor 334 of the joint portion 33 is provided with a brake portion 335 for braking the vertical movement of the robot arm 24 . In this embodiment, an electromagnetic brake is used as the brake portion 335 and the electric motor 334 has the brake portion 335 built therein.
In addition, the electric motor 334 is provided with a position detector 45 that detects the angle of the rotary shaft 333 to detect the vertical position (height position) of the robot arm 24 . An encoder, for example, is used for the position detection unit 45 .

Further, a brake switch 44 is arranged on an operation portion (not shown) of the robot main body 11 . The brake switch 44 issues an operation release command for releasing the operation of the brake unit 335 to the brake control unit 4 when the robot 1 is in a stopped state (non-operating state of the servo control system). For example, the brake switch 44 is operated by the operator in height adjustment work such as origin setting work of the robot arm 24 .

Returning to the description of the brake control unit 4, first, the motor control driver 42 is a control integrated circuit (IC: Integrated Circuits) having at least a pulse output function, a general purpose input/output (GPIO) function, and a position information acquisition (encoder counter) function. It is configured. The motor control driver 42 rotates the electric motor 334 via the servo driver 43 when movement control information for the robot arm 24 is input from the host computer 41 . Rotation of the electric motor 334 causes the robot arm 24 to move vertically via the pinion 332 and the rack 331 shown in FIG.
Further, when the electric motor 334 rotates, the vertical position of the robot arm 24 is detected by the position detector 45 . The detected position information is output to the motor control driver 42 through the servo driver 43 . The motor control driver 42 acquires position information.
Furthermore, operation information including release of the operation of the brake portion 335 by operating the brake switch 44 is output to the motor control driver 42 .

As described above, the host computer 41 outputs the movement control information to the motor control driver 42 and further outputs the operation release information for controlling the actuation or release of the brake to the motor control driver 42 .
The motor control driver 42 outputs movement control information to the servo driver 43 , and the servo driver 43 drives the electric motor 334 . Operation cancellation information is output from the motor control driver 42 to the servo driver 43 , and the servo driver 43 controls the brake section 335 .
In the host computer 41, the position information detected by the position detector 45 is input through the servo driver 43 and the motor control driver 42, respectively. In addition, operation information from the brake switch 44 is output to the motor control driver 42 , and the motor control driver 42 outputs the operation information to the host computer 41 as an operation release command for releasing the operation of the brake unit 335 .

The host computer 41 compares the position information with the reference value.
As the position information, position information converted from angle information into height position information of the robot arm 24 in an encoder calculation circuit (not shown) incorporated in the host computer 41 is used.
The reference value is stored in advance in the storage unit 441 built into the host computer 41 . In this embodiment, position information (height position information) detected in the previous height adjustment work is used as the reference value stored in the storage unit 441 . In other words, the positional information stored in the storage unit 441 before the motor control driver 42 issues the operation release command generated by operating the brake switch 44 to the host computer 41 is used as the reference value. ing.
As the storage unit 441, a storage device externally attached to the host computer 41 can be used.

As a result of comparison between the position information and the reference value, the host computer 41 provides operation release information for alternately operating and releasing the brake unit 335 in response to the operation release command when the position information is equal to or less than the reference value. is output to the brake unit 335 . On the other hand, when the position information exceeds the reference value as a result of the comparison between the position information and the reference value, the host computer 41 sends operation release information to the brake unit 335 to release the operation of the brake unit 335 in response to the operation release command. Output.

(Brake control method and program for robot 1)
A brake control method for the robot 1 and a program for causing a computer to execute this brake control method will be described with reference to FIGS. 1 to 3 and FIG.
When the brake control method of the robot 1 is started, the power of the robot 1 is first turned on, and the current height position information of the robot arm 24 shown in FIG. 1 is initialized (step S1).

Here, height adjustment work is started, and it is determined whether or not there is a request to release the operation of the brake section 335 in the robot arm 24 that moves in the vertical direction (step S2). A request to release the operation means that the brake switch 44 shown in FIG. 3 has been operated and an operation release command has been issued. Conversely, when there is no request to release the operation, it means that the brake switch 44 has not been operated and the operation release command has not been issued.
When it is determined that there is no request to release the operation, the brake section 335 operates (step S9). Thereby, the robot arm 24 is braked by the brake portion 335 . Then, it is determined whether or not the height adjustment work is completed (step S8). When it is determined that the height adjustment work has ended, this brake control method ends. If it is determined that the height adjustment work has not been completed, the process returns to step S2.

On the other hand, when it is determined in step S2 that there is a request to release the operation of the brake section 335, the current height position information of the robot arm 24 is detected using the position detection section 45, and the motor control driver 42 It is acquired (step S3, see FIG. 3).
Subsequently, it is determined whether or not the brake portion 335 of the robot arm 24 is operating (step S4). If it is determined that the brake portion 335 is operating, the operation of the brake portion 335 is released (step S5).
At this time, the position information acquired in step S3, that is, the current height position information of the robot arm 24 is stored in the storage unit 441 (step S6). This stored position information is used as a "reference value" in the next height adjustment work.
Then, the standby state is entered, and the state in which the operation of the brake portion 335 is released is maintained for a certain period of time (step S7). Here, the constant time (standby time) is set to 200 [msec], for example. After the standby state, the process moves to step S8.

If it is determined in step S4 that the brake unit 335 is not operating, the current height position information of the robot arm 24 obtained in step S3 and the reference value stored in the storage unit 441 (see FIG. 3) are combined. are compared (step S10). The "reference value" to be compared here is the height position information of the robot arm 24 stored in the storage unit 441 in the previous height adjustment work.
At step S10, there is a request to release the operation of the braking portion 335 at step S2. That is, at step S10, the brake switch 44 shown in FIG.

In this step S10, when the height position information is equal to or less than the reference value, the brake section 335 is operated (step S11). After that, the process moves to step S6.
On the other hand, when the height position information exceeds the reference value in step S10, the process proceeds directly to step S6.

That is, in the brake control method, when the height adjustment work is not completed in step 8, the processing from step S2 to step S11 is repeated. Therefore, in step S10, when the height position information is equal to or less than the reference value, in other words, when the height position is lower than the previous height position, the operation of the brake portion 335 and the release of this operation are performed in response to the operation release command. are performed alternately. The switching time between activation and deactivation corresponds to standby time. In other words, since the robot arm 24 is moving downward when the reference value is less than the reference value, the braking portion 335 is alternately operated and released to effectively suppress the rapid drop of the robot arm 24 . or can be prevented.
Further, in step S10, when the height position information exceeds the reference value, in other words, when the height position is higher than the previous height position, the operation of the brake portion 335 is released in response to the operation release command. In other words, when the reference value is exceeded, the robot arm 24 moves upward. Therefore, when the operation of the brake unit 335 is released, the movement of the robot arm 24 upward as a specific direction is smooth. can be done

(Effect)
As described above, the robot 1 according to this embodiment includes the position detection section 45, the brake section 335, and the brake control section 4, as shown in FIG. The position detector 45 detects the height position of the robot arm 24 shown in FIGS. The brake unit 335 brakes the robot arm 24 moving vertically.
Here, based on the height position detected by the position detection unit 45, the brake control unit 4 alternately operates and releases the brake unit 335. As shown in FIG. Therefore, the operation of the brake portion 335 can be released in the upward direction as the specific direction, so that the robot arm 24 can be smoothly moved upward.

In the robot 1, the brake control unit 4 shown in FIG. 3 compares the height position of the robot arm 24 with a reference value (step S10 in FIG. 4). When there is a command to release the operation of the brake unit 335, that is, an operation release command, the brake control unit 4 activates and releases the brake unit 335 when the height position is equal to or lower than the reference value. Alternate. On the other hand, the brake control unit 4 releases the operation of the brake unit 335 when the height position exceeds the reference value.
For this reason, in the upward direction in which the height position exceeds the reference value as a specific direction, the actuation of the braking portion 335 is released, so that the robot arm 24 shown in FIGS. 1 and 2 can be smoothly moved upward. can be made

Furthermore, the robot 1 includes a storage unit 441 that stores height positions as position information, as shown in FIG. The reference value to be compared with the height position in the brake control unit 4 is the position information stored in the storage unit 441 before issuing the operation release command, that is, before releasing the operation of the brake unit 335 .
Therefore, the robot arm 24 can be smoothly moved in a specific direction (for example, the height direction) based on the position information stored before the issuance of the deactivation command.

The robot 1 is a horizontal articulated robot, and the robot arm 24 moves vertically. Therefore, in the horizontal articulated robot, the robot arm 24 can be smoothly moved upward as a specific direction.

Further, a program for causing a computer to execute a brake control method for the robot 1 including the position detection unit 45, the brake unit 335, and the brake control unit 4 shown in FIG. 3 includes the following steps. The position detector 45 detects the height position of the robot arm 24 (step S3 in FIG. 4). A braking portion 335 brakes the robot arm 24 . The brake control unit 4 compares the height position detected by the position detection unit 45 with the reference value. The brake control unit 4 alternately actuates and releases the brake unit 335 when the height position is equal to or lower than the reference value when there is an operation release command to release the operation of the brake unit 335 . Also, the brake control unit 4 releases the operation of the brake unit 335 when the reference value is exceeded.
Therefore, it is possible to provide a program capable of smoothly moving the robot arm 24 when releasing the brake portion 335 and moving the robot arm 24 upward as a specific direction.

[Second embodiment]
A program for causing a computer to execute the robot 1 and its brake control method according to the second embodiment of the present invention will be described with reference to FIGS. 5 and 6. FIG.
In the present embodiment, the same or substantially the same constituent elements as those of the robot 1 according to the first embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted.

(Overall Configuration of Robot 1)
As shown in FIG. 5, the robot 1 according to this embodiment is configured as a vertically articulated robot. Specifically, the robot 1 includes a robot main body 11 including a plurality of robot arms 51 to 55 and a plurality of joints 61 to 66, and a brake control section 4. As shown in FIG.
Each component will be described in detail below.

(1) Configuration of Robot Arms 51 to 55 and Joint Portions 61 to 66 As shown in FIG. 5, in the robot main body 11, a joint portion 61 as a rotary joint is arranged on a base portion (not shown). The joint portion 61 is configured to rotate relative to the base portion in the horizontal direction indicated by the arrow E. As shown in FIG. A lower end portion of the robot arm 51 is connected to the joint portion 61 . The robot arm 51 is erected upward from the joint portion 61 and is also formed in a cylindrical shape. A joint portion 62 as a rotary joint is provided at the upper end portion of the robot arm 51 .

One end of a robot arm 52 extending in the Y-axis direction and having a cylindrical shape like the robot arm 51 is connected to the joint 62 in the state shown in FIG. The robot arm 52 is configured to rotate by a joint portion 62 in the vertical direction indicated by the arrow F (Y-axis-Z-axis vertical plane direction) and move in the vertical direction. The other end of the robot arm 52 is provided with a joint portion 63 as a rotary joint similar to the joint portion 62 .

One end of a robot arm 53 extending in the Y-axis direction and having a cylindrical shape like the robot arm 51 is connected to the joint 63 . The robot arm 53 is configured to rotate in the vertical direction indicated by the arrow G, which is the same as the vertical direction indicated by the arrow F, by means of a joint portion 63 and move vertically. The other end of the robot arm 53 is provided with a joint portion 64 as a rotary joint similar to the joint portion 61 .

One end of a robot arm 54 extending in the Y-axis direction and having a cylindrical shape like the robot arm 51 is connected to the joint 64 . The robot arm 54 is configured to be rotated by a joint portion 64 in the vertical direction indicated by the arrow H (X-axis-Z-axis vertical plane direction). The other end of the robot arm 54 is provided with a joint portion 65 as a rotary joint similar to the joint portion 62 .

One end of a robot arm 55 extending in the Y-axis direction and having a cylindrical shape like the robot arm 51 is connected to the joint 65 . The robot arm 55 is configured to rotate by a joint portion 65 and move vertically in the vertical direction indicated by the arrow I, which is the same as the vertical direction indicated by the arrow F. As shown in FIG. The other end of the robot arm 55 is provided with a joint portion 66 as a rotary joint similar to the joint portion 61 .

The joint 66 is configured to rotate in the vertical direction indicated by arrow J, which is similar to the vertical direction indicated by arrow H. A tool (not shown) can be attached to the joint portion 66 .

Here, the configurations of the joints 61, 64, 66 of the robot body 11 are the same as or substantially the same as the configurations of the joints 31, 34 of the robot body 11 according to the first embodiment. It is
On the other hand, each of the joints 62, 63, 65 has the same or substantially the same configuration as the joint 32 according to the first embodiment. As shown in FIG. 6, the joint part 62 has an electric motor 621, and the rotating shaft of the electric motor 621 is connected to one end of the robot arm 52 either directly or via a speed reducer (not shown). The configuration of each of the joints 63 and 65 is the same as the configuration of the joint 62, so the description of the configuration is omitted.

(2) Configuration of Brake Control Unit 4 In this embodiment, the brake control unit 4 and the brake control method according to the first embodiment are used to control the braking of the robot arms 52, 53, and 55 that move in the vertical direction. and the same brake control unit 4, brake control method and program as the program are applied.
That is, the brake control unit 4 according to the present embodiment includes the host computer 41, the motor control driver 42 and the servo driver 43 shown in FIG. 3 described above. In the robot body 11, the brake switch 44 shown in FIG. 3 is arranged, and the electric motor 621 of the joint section 62 is arranged with a brake section corresponding to the brake section 335 and a position detection section corresponding to the position detection section 45. is set. The electric motors (not shown) of the joints 63 and 65 have the same configuration as the electric motor 621 .

(Brake control method and program for robot 1)
Also, the brake control method and the program for causing the computer to execute the brake control method are the same as the brake control method and program according to the first embodiment, and thus descriptions thereof will be omitted here.

(Effect)
As described above, according to the robot 1 according to the present embodiment, it is possible to obtain the same effects as those obtained by the robot 1 according to the first embodiment.
Further, according to the program for causing a computer to execute the brake control method for the robot 1 according to the present embodiment, it is possible to obtain the same effects as those obtained by the program according to the first embodiment.

Further, as shown in FIG. 5, the robot 1 is a vertical articulated robot in which the robot arm 52, the robot arm 53, and the robot arm 55 are vertically articulated by joints 62, 63, and 65, respectively. move in the direction Therefore, in the vertical articulated robot, the robot arms 52, 53, and 55 can be smoothly moved with the vertical direction as the specific direction.

[Other embodiments]
The present invention is not limited to the above embodiments, and can be modified in various ways without departing from the scope of the invention.
For example, the present invention may form the robot arm in the shape of a rectangular tube. Further, the present invention is not limited to the brake control method for vertical movement of the robot arm, but may be a brake control method for movement in each of horizontal, oblique, and rotational directions.

1 robot 11 robot body 21-24, 51-55 robot arm 31-34, 61-66 joint 334, 621 electric motor 335 brake unit 4 brake control unit 41 host computer 42 motor control driver 43 servo driver 44 brake switch 45 position Detection unit

Claims (5)

a position detection unit that detects the position of the robot arm;
a brake unit that brakes the robot arm;
a brake control unit that alternately operates and releases the brake unit based on the position detected by the position detection unit ;
The brake control unit compares the position with a reference value, and when there is a command to release the operation of the brake unit and the position is equal to or lower than the reference value, the brake unit is operated and the operation is stopped. A robot that alternately performs a release and a release, and releases the operation of the brake unit when the reference value is exceeded . Further comprising a storage unit that stores the position as position information,
2. The robot according to claim 1 , wherein the reference value is the position information stored in the storage section before the instruction. The robot according to any one of claims 1 and 2, wherein the robot arm is a vertically movable robot arm of a horizontal articulated robot. The robot according to any one of claims 1 and 2, wherein the robot arm is a robot arm of a vertical articulated robot that rotates vertically about a joint portion. A program for causing a computer to execute a brake control method for a robot comprising a position detection unit, a brake unit, and a brake control unit,
a step in which the position detection unit detects the position of the robot arm;
a step in which the brake unit brakes the robot arm;
The brake control unit compares the position detected by the position detection unit with a reference value, and when there is a command to release the operation of the brake unit, when the position is equal to or less than the reference value, the a step of alternately activating and deactivating the braking portion, and deactivating the braking portion when the reference value is exceeded;
program with .

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